Consequent of advancements in optical technology and semiconductor processing techniques, liquid crystal displays (LCD) have become widely applied to electronic devices, such as display devices of consumer electronics or computer products including portable computers, portable televisions, mobile phones, video cameras, desktop displays and projection televisions, and have become the primary trend of display technology because of advantages including high picture quality, small volume, light weight, low voltage driving, low consumption power and wide applicability.
Typically, a liquid crystal display of a portable computer is fixed to a top cover of the portable computer. When using the portable computer, the liquid crystal display can be shown when the top cover is opened. The top cover is usually connected with the computer mainframe by a shaft. The liquid crystal display of the portable computer can be adjusted to the desired viewing angle of a user by adjusting the angle of the top cover.
Because it is easily carried, the user usually carries the portable computer with him for dealing with daily work. Different working environments require the portable computer to embody various displays to increase the presentation ability of the user. However, the portable computer is limited to a specific display angle range, so the audience nearby and especially seated laterally to the computer cannot clearly see an image shown on the display. In addition, as the software industry has continually changed, computer operating systems have combined a touch-sensitive writing input function, so many companies have produced various tablet computers with touch-sensitive screens. The writing input directly communicates the operation instructions into the computer system (e.g. a display monitor) by a writing device (e.g. a writing pen). The recently developed convertible tablet computer offers an innovative writing input function that has changed the usage habits of the computer and has made the information industry reach a whole new milestone. The convertible tablet computer combines the human pen-writing function of the tablet computer and the keyboard-inputting function and the easy mobility of the portable computer. The convertible tablet computer is effectively designed according to the user that needs to move about often and includes a human input interface and a liquid crystal monitor that can rotate by 180 degrees, so the convertible tablet computer can be easily carried and the persons watching nearby can easily read the data shown on the display.
The rotating of the monitor of the tablet computer typically is achieved in two ways. FIG. 1 is a three-dimensional diagram of a conventional portable computer. A conventional portable computer 10 comprises a mainframe unit 20 and a display unit 30, wherein the display unit 30 rotates about an axis 40 and along the direction designated by an arrowhead 45, so as to convert between a keyboard-inputting state and a writing-inputting state.
FIG. 2A is a cross-sectional view of another conventional portable computer. A conventional portable computer 50 comprises a mainframe unit 60, a display unit 70 and a supporting assembly 80, wherein two ends of the supporting assembly 80 are respectively installed on two sides of the mainframe unit 60 and two sides of the display unit 70 to connect the mainframe unit 60 and the display unit 70.
FIGS. 2B and 2C are cross-sectional views of the portable computer in FIG. 2A in a keyboard-inputting state. In FIG. 2B, in the keyboard-inputting state, the display unit 70 rotates following the supporting assembly 80 and along the direction designated by an arrowhead 91. Then, a display surface 71 of the display unit 70 is obliquely deposed over an operation interface 61 of the mainframe unit 60, such as shown in FIG. 2C.
FIG. 2D is cross-sectional view of the portable computer in FIG. 2A in a writing-inputting state. In the writing-inputting state, the display unit 70 rotates up and down along the direction designated by an arrowhead 93 by using the supporting assembly 80 as a fulcrum, so as to make a backside surface 73 of the display unit 70 stack on the operation interface 61 of the mainframe unit 60 and to levelly depose and expose the display surface 71 of the display unit 70 for written input.
However, the aforementioned portable computers have the following disadvantages. The display of the portable computer in FIG. 1 has a flipping function; however, the liquid crystal display usually shakes in practical operation, resulting in unstable displaying. The display of the portable computer shown in FIGS. 2A through 2D rotates up and down by using the supporting assembly installed in the two sides of the portable computer; however, the operation of the supporting assembly installed in the two sides is inconvenient, and the aesthetic design of the portable computer is hampered.
Therefore, designers, manufacturers and users desire to improve the supporting assembly used to connect the mainframe unit and the display unit such that it can easily change various operation positions of the display unit to provide a stable inputting and displaying environment for the users.